Electric-arc lamp.



C. E. HARTHAN.

ELECTRIC ARC LAMP. (Application med oct. 2s, 1900.)

No. 697,482. Patented Apr. I5, i902.

(No Model.)

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.2 is a rear elevation.

vUNITED STATES- PATENT OFFICE."

CHARLES E. HARTHAN, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 697,482, dated April 15, 1902. Application tiled 'October 23,1900. Serial No. 34,052. (No model.)

To all whom it may concern:

Be it known that I, CHARLES E. HARTHAN, a citizen of the United States, residing at Lynn, in the county of Essex, Stateof Massachusetts, have invented certain new and useful Improvements in Electric-Arc Lamps,

(Case No. 1,703,) of which the following is a specification.

The present invention relates to electric headlights, and is primarily designed for use on locomotives; but it can be applied to other uses, if desired.

The object of the present invention is to provide an arc-lamp or headlight which demands little attention and is simple in construction, as will be more fully described and claimed hereinafter.

In the accompanying drawings, Figure 1 is a sectional View of my improved lamp. Fig. Fig. 3 is a plan view, and Fig. It is a diagram illustrating certain of the parts in perspective and also the circuit connections.

In the drawings, A represents a rectangular box-like support, and to an extension on the base thereof is secured-a studvB, which supports the reflector C. Located above the base-plate and extending parallel therewith is a plate A', whichl forms ay support for the actuating-magnets D and D and also for the plate E, which supports the lower-carbon holder and also the globe-holder F. The arc formed between the carbons is inclosed in a small glass cylinder, having restricted ends, with which the carbons make acomparatively tight fit. By this arrangement air has difficult access to the interior of the cylinder. The opposite ends of the globe are similar in construction, so that eitherl end can be placed in the globe-holder F. The end of the globe is provided with a bead G, with which the device for securing the globe engages. This construction enables me to do away with the gas-cap ordinarily employed. The reflector C is cut away at C' to receive the upper carbon and its holder H, and it is also cut away at C2 to receive the lower carbon.

Screw-threaded to the top A' of the box-like base are two vertically-extending rods I and I'. These rods are connected at the top by a plate I2, which is retained in place by screws and nuts. The rods act as guides for the upper-carbon holder I-I and its extension H', the latter being insulated from the holder. Situated on opposite sides of the guide-rods are 5 5 two long solenoid-magnets D and D. These magnets are secured to the plate A' by means of screws and are connected atthe top by a metal plate D2. The plate D2 is provided with projections containing holes, and pass- 6o ing through these holes are the guide-rods I and I. This arrangement serves to stiffen and -hold the guide-rodsl 'in place. On the under side of the plate D2 is formed a projection D3, and pivotally secured thereto is the cylinder of a dash-pot, the piston of which is pivotally secured to the iron armature-yoke J, which connects the solenoid-cores K and K.

The cores K and K' are composed'of long thin rods containing Very little iron, so as to 7o be saturated when very little current is flowing in the windings, and the relation between the coils and their cores is such that the cores are capable of maintaining a substantially uniform pull over a wide range of movement. 7 5 As here shown, the cores will maintain a practically constant pull for a distance equal .to about two-thirds of the total length of the core. In other words, the yoke J can travel from its uppermost position to a point 8o where it will almost touch the base A of the casting, and during allot' this movement the pull will be substantially constant. Extending upward from the yoke J is a rod L, which passes through openings in tho plate Al and in the plate D2, the base and plate forming guides therefor. l To the upper end of the rod is secured the extension H of the upper-carbon holder. By this arrangement it will be seen that the Weight of the upper carbon and 9o holder is directly supported when the lamp is in operation by the solenoid-cores,without the intervention of any clutch whatsoever. This is an especially desirable arrangement, since it dispenses with all clutches and their operating mechanism. It is particularly important on locomotives, where the jarring is considerable and where it is of the utmost importance that the light be constantly maintained. I am also enabled to make a lamp roo which is very small and compact.

The lowcr end of the combined globe and lower-carbon holder is provided with a shouldered portion which iits into the plate E, which plate is insulated from the base-plate A in any suitable manner. By means of the screw M the globe, its holder, and the lower carbon may be removed or secured in place at will.

Mounted on the base are suitable bindingposts N and O. From the binding-post O a connection is extended to the aro-steadying resistance I), which is wound in any suitable manner and is retained in place on the base.

Referring to Fig. 4, the connection and operation of the lamp will be readily understood. N and O represent the binding-posts, and the path of the current is from the binding-post N through a connection to the solenoid D, thence to the solenoid D', and to the upper-carbon holder II. The current then passes to the lower carbon and thence to the resistance P and to the binding-post O. IVhen the current is cut ott from the lamp, the upper carbon and its holder will drop until the ends of the carbons touch. At the same time the yoke .I andthe two solenoid-cores K and K also drop by reason of their being directly connected with the holder.

On account of the arc beinglong, and therefore not requiring delicate feeding mechanism to maintain it, and also being surrounded by an inclosure to which the air has difficult access, I am enabled to make a lamp which is very simple in construction and one which will burn for a considerable number of hours without materially changing the position of the arc with respect to the center of the reiiector. As a general thing, it is best in retrimming to have the end of the lower carbon somewhat above the center of the reileotor, so that as the carbon is consumed the are willbe changed from a point slightly above said center to a point slightly below. The solenoid-cores II and K are connected by a yoke at the bottom, but are free at the upper ends. This means that there is a certain amount of free magnetism at the upper ends, which tends to blow out the arc between the carbons. To obviate this, a plate of magnetic material Q is placed between the coils and cores and the are. The plate is slotted on the upper side to permit the carbon-holder to move up and down and is retained in place by screws, which pass through feet Q, form ed on the bottom.

I have used mechanism of the character mentioned above in connection with focusinglamps, and I aim to embrace such use in the claims.

VhatI claim as new, and desire to secure by Letters Patent of the United States, is-

l. In an electric-arc lamp, the combination of a fixed carbon-holder, a movable carbonholder, a magnet located below the movable holder, an armature situated below and movable toward or away from the magnet, a rod @evase extending from the armature to the holder and forming the sole actuating means, guides for the rod, and guides for the carbon-holder.

2. In an arc-lamp, the combination of a boxlike support, a retleotor, an extension on the support to which the reflector is secured, a pair of solenoid-magnets, movable cores therefor, a yoke connecting the cores, a carbonholder, a guide for the holder, and a rod which is secured to the yoke and the holder Y so that as the carbons are consumed, the position of the core within the solenoid varies for a given length of are.

3. In an electric-arc lamp, the combination of abase, apair of solenoids mounted thereon, a head or plate connecting the solenoids at the top and acting also as a guide, an armature for the solenoids, a carbon-holder, a rod connecting the armature and said holder which passes through the head and is guided thereby, and a pair of guides on which the holder travels.

fi. In an electric-arc lamp, the combination of a box-like base, a pair of solenoids secured to the outside of the box, a core Afor each solenoid, a yoke for connecting the cores which is located within the box, a head or plate connecting the magnets, a dash-pot, one portion of which is secured to the plate and the other portion to the yoke within the box.

5. In an electric-arc lamp, the combination of a combined globe and carbon holder, a clamp for holding the globe, means for securing the carbon, a support for the holder comprising a plate having a slotted opening` and extending ears, and a clamping-screw for drawing the ears together in a manner to secure the holder.

(i. In an electric-arc lamp, the combination of a base, an actuating-magnet, a core therefor having a certain amount of free magnetism, carbons situated at one side of the magnet, and a plate of magnetic material located between the carbons and the magnet, which shields the arc from the stray magnetism of the magnet and core.

7. In an electric-arc lamp, the combination of a ixed carbon-holder, a movable carbonholder, a base, a pair of magnets mounted on the base, a plate connecting the magnets at their upper ends, a core for the magnets,- a rod situated between the magnets vfor connecting the core with the movable carbonholder, which rod passes through the plate and is guided thereby, and a pair of vertically-extending rods which pass through the plate to the upper-carbon holder and act as guides therefor.

In witness whereof I have hereunto set my hand this 20th day of October, 1900.

CHARLES E. IIARTIIAN.

IVitnesses:

DUGALD MoKiLLor, HENRY O. WnsTnNnAnr.

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